BMW 8 Series (G14) (2019) is 385 mm (15.16 inch) longer, 99 mm (3.90 inch) wider, 69 mm (2.72 inch) higher and has 166 liters (5.86 ft3) bigger cargo space than Porsche 718 Cayman (2020).
Porsche 718 Cayman (2020) is 472 kg (1,041 lbs) lighter than BMW 8 Series (G14) (2019).